Branching pattern characteristics and anti-windbreakage ability of Pinus thunbergii in sandy coast

沙质海岸空间梯度上环境差异较大,黑松(Pinus thunbergii)在长期的适应过程中树冠结构变化也很大.为揭示黑松树冠结构与环境间的适应机制,在山东省胶南市灵山湾国家森林公园距海岸线0-50、200-250和400-450 m梯度内各设置1个样带,记为带Ⅰ、带Ⅱ、带Ⅲ,采用枝构型的理论和方法,对黑松的分枝格局进行了研究,并采用模拟自然风法测定了黑松枝条的抗风折能力.结果表明:1）在海岸梯度上黑松分枝格局差异较大,随着距离海岸越来越远,黑松各级枝的分枝长度、总体分枝率均逐渐增大,而枝径比和逐步分枝率逐渐减小,各级分枝角度表现为带Ⅰ＞带Ⅲ＞带Ⅱ.2）带Ⅰ树冠背风面与迎风面相比,分枝长度、分枝角度、分枝数量、枝条干枯率分别是迎风面的1.62、1.38、2.65和0.59倍,随着距离海岸越来越远,这种不对称性逐渐减弱,至带Ⅲ树冠基本对称.3）海风是影响带1分枝角度偏转、枝条干枯和冠型不对称现象的主要原因.4）带Ⅲ枝条的抗风折能力高于带Ⅰ,且两个样带模拟风速与枝条所承受的拉力之间的关系均符合逻辑斯蒂方程,相关系数R2均达0.97以上.该研究揭示了不同海岸梯度上黑松分枝格局的形成机制及其抗风折能力,可为沿海黑松防护林的合理经营提供科学依据.     

The effects of dietary fermented wheat bran polysaccharides on mucosal and serum immune parameters,hepatopancreas antioxidant indicators,and immune-related gene expression of common carp (Cyprinus carpio) juveniles

Aquaculture research has focused on polysaccharides as they are among the most promising new-generation immunostimulant used to control aquatic diseases. The aim of this study was to investigate the immunomodulatory effects of fermented wheat bran polysaccharides (FWBPs) on juvenile common carp (Cyprinus carpio). Carps were fed different FWBP amounts (0%, 0.1%, 0.2%, and 0.4%) for 8 weeks and then their skin mucus and serum immune parameters, hepatopancreas antioxidant indicators, and immune-related gene expression in the intestines, kidneys, and spleen were measured. The skin mucus IgM levels significantly increased in 0.1% FWBP group, but decreased in 0.4% FWBP group. The skin mucus protease and the serum alkaline phosphatase activities increased significantly in the 0.2%, 0.1%, and 0.4% FWBP groups, respectively. The serum total Ig levels increased noticeably in the 0.1% and 0.2% FWBP groups. The highest and lowest serum lysozyme activities were observed in the 0.1% and 0.4% FWBP groups, respectively. The hepatopancreatic total superoxide dismutase activity was higher in the 0.1% FWBP group than in the control. The malondialdehyde levels decreased significantly in the 0.2% and 0.4% groups. The intestinal mRNA levels of the LZM-C and IL-10 genes were significantly higher in the 0.2% than in the 0.4% FWBP group; TNF-α was significantly upregulated in the 0.1% group. The gene expression in the kidneys did not differ significantly among the treatments, except for a significant increase in the IL-10 expression in the 0.1% treatment. Significantly elevated expression of LZM-C in 0.2% group and IL-10 in 0.1% group was observed in the spleens. TNF-α and IL-1β were significantly downregulated in the 0.4% group. These results suggest that FWBPs could be used as immunostimulant feed additives in common carp cultures.

     

Molecular cloning and functional analysis of goose interferon gamma

The cDNA for goose interferon gamma (goIFN-gamma) was cloned from PHA-stimulated goose peripheral blood mononuclear cells (PBMCs) by RT-PCR. This cDNA encodes a 19-amino acid signal peptide and a 145-amino acid mature protein, which shares a high homology with duck IFN-gamma. Recombinant mature goose interferon gamma (rgoIFN-gamma) generated from both prokaryotic and eukaryotic expression systems effectively inhibited the replication of goose paramyxovirus and recombinant vesicular stomatitis virus in vitro. These antiviral activities were abrogated by rabbit anti-rgoIFN-gamma antibodies in vitro. Furthermore, rgoIFN-gamma stimulated goose peritoneal macrophages to produce nitric oxide (NO) in vitro, demonstrating its macrophage activating factor (MAF) activity. Therefore, the availability of bioactive rgoIFN-gamma and its specific antibodies provides valuable tools for studying T cell immunity in geese.     

MDV Meq-clustered miRNAs基因缺失BAC克隆株的构建及其体外增殖特性

为构建缺失马立克氏病病毒(Mareks disease virus,MDV)Meq基因簇microRNAs(Meq-clustered miRNAs的突变株,本研究在vv MDV GX0101细菌人工染色体(bacterial artificial chromosome,BAC)克隆的基础上,采用Red/ET同源重组技术将Meq-clustered miRNAs的编码基因进行缺失突变,经PCR鉴定及序列分析证明Meq-cluster miRNAs序列成功缺失后,提取Δmeq-miRNAs BAC DNA,转染鸡胚成纤维细胞(CEF)进行病毒拯救,用SYBR GreenⅠqRT-PCR检测病毒体外增殖特性。结果表明成功拯救出缺失MDV Meq-clustered miRNAs基因的感染性BAC克隆株GX0101Δmeq-miRNAs,且该缺失株与亲本株GX0101BAC具有相似的增殖曲线,Meq-clustered miRNAs是MDV体外复制的非必需基因。MDV Meq-clustered miRNAs基因缺失感染性BAC克隆株的成功构建为进一步研究MDV Meq-clustered miRNAs在MDV致病和致肿瘤方面的作用奠定了基础。     

Growth,microtuber production and physiological metabolism in virus-free and virus-infected potato in vitro plantlets grown under NaCl-induced salt stress

Viral diseases (a biotic stress) and salinity (an abiotic stress) have been/are the two major constraints for sustainable development of the world’s agricultural production including potato. Crops grown in field are often exposed simultaneously to abiotic and biotic stress, and responses of plants to co-stress by two or more factors may differ from those to each of the multiple stresses. Using in vitro cultures, we demonstrated that virus infection (singly and in combination) or salt, and co-stress by virus infection (singly and in combination) and salt significantly reduced growth and microtuber production, and caused severely oxidative cell damage determined by levels of O₂·^? and methane dicarboxylic aldehyde, and H₂O₂ localization in situ. Alterations in physiological metabolism by increasing total soluble sugar and free proline, and by decreasing chlorophyll content are responses of potato plantlets to virus infection (singly and in combination) or salt stress and co-stress by virus infection (singly and in combination) and salt. Oxidative cell damage and reduced chlorophyll content caused by virus and/or salt are believed to be responsible for the reduced growth, eventually resulting in decreased tuber yield. Results reported here would help us to better understand possible mechanism of reduced tuber yield by virus infection and/or salt stress.     

黄土区长期封育草地优势物种生态位宽度与生态位重叠对不同干扰的响应特征

运用Levins生态位宽度指数和Pianka生态位重叠指数及物种丰富度,初步分析了长期封育草地优势种群生态位对放牧、火烧和施肥的响应特征。结果表明:在封育(对照组)、放牧、火烧和施肥干扰下,生态位宽度最大的物种依次是白颖苔草、中华小苦荬、白莲蒿和本氏针茅;建群种本氏针茅在不同干扰下生态位宽度表现为施肥(1.362)>火烧(1.244)>封育(1.088)>放牧(1.026),物种丰富度指数则依次为放牧>施肥>火烧>封育。所有物种和优势种的生态位重叠指数平均值均表现为施肥>封育>火烧>放牧,且在各干扰下,生态位重叠指数最大的种对依次为本氏针茅和白颖苔草、大针茅和白颖苔草、大针茅和白颖苔草以及中华小苦荬和硬质早熟禾。综上所述,对长期封育的草地进行适度的干扰可提高物种丰富度,改善种群的生态位配置和最大限度地利用环境资源。     

大豆田节肢动物群落时间格局

2004年对长春南郊大豆田节肢动物群落进行调查,通过网捕和地面调查共获得节肢动物种类213种,其中天敌98种,害虫63种,中性昆虫52种;利用物种丰富度、多样性和均匀度分析群落时间格局,结果表明:伴随大豆整个生育期节肢动物群落经历发展、鼎盛和衰退3个过程,在高毒化学农药使用后群落的丰富度和多样性明显降低。最后对大豆田害虫生态调控技术进行了讨论。     

Polyphenol content of plasma and litter after the oral administration of green tea and tea polyphenols in chickens

Metabolic profiles of broiler chickens were examined after the ingestion of green tea, tea polyphenols, and (-)-epigallocatechin-3-gallate (EGCG). Solid-phase extraction of serum and litters yielded free catechins and their metabolites, which were then identified and quantified by liquid chromatography-tandem mass spectrometry. In plasma samples, (-)-gallocatechin, (+)-catechin, and EGCG were detected in the green tea group; pyrogallol acid, (epi)catechin-O-sulfate, 4'-O-methyl-(epi)gallocatechin-O-glucuronide, and (epi)catechin-3'-O-glucuronide were detected in the tea polyphenols group; and EGCG, (-)-gallocatechin gallate (GCG), and 4'-O-methyl-(epi)gallocatechin-O-glucuronides were detected in the EGCG group. In litters, gallic acid, EGCG, GCG, and ECG were detected in the green tea and tea polyphenols groups; EGCG and ECG were detected in the EGCG group. The conjugated metabolites, 4'-O-methyl-(epi)gallocatechin-O-glucuronide, (epi)catechin-3'-glucuronide, and 4'-O-methyl-(epi)catechin-O-sulfate, were identified in the green tea group; 4'-O-methyl-(epi)catechin-O-sulfate and 4'-O-methyl-(epi)gallocatechin-O-sulfate were identified in the tea polyphenols group; only 4'-O-methyl-(epi)gallocatechin-O-sulfate was detected in the EGCG group. The excretion of tea catechins was 95.8, 87.7, and 97.7% for the green tea, tea polyphenols, and EGCG groups, respectively.     

X射线CT确定土壤大孔隙结构

Undisturbed soil core with many macropores and disturbed soil core with only one macropore (diameter is 10 mm) were probed by x-ray computed tomography (CT). The size, number, shape and continuity of macropores in the transverse and vertical sections of soil were characterized using CT scanning images. The probability densities of macropores in the transverse section of soil core exhibited a logarithmic F distribution. Results indicated that CT scanning was a promising nondestructive method for characterizing macropores in soils.     

半滑舌鳎性别决定的QTL互作研究

半滑舌鳎（Cynoglossus semilaevis）成体雌雄差异较大,性别控制是提高半滑舌鳎养殖效益的有效手段,而实现性别控制的关键在于揭示半滑舌鳎的性别决定的遗传机制。半滑舌鳎的遗传性别决定方式为ZW型,这种性别决定方式可能存在多因子剂量效应,其性别决定不仅与性染色体有关,常染色体也会参与性别调控,遗传性别是性染色体和常染色体的协同作用的结果。本研究从数量性状基因座（quantitative trait loci,QTL）互作的角度来探讨半滑舌鳎遗传性别决定机制,将性别作为二项性状,利用半滑舌鳎高密度微卫星遗传连锁图谱,采用logistic回归模型扫描所有标记间的二阶组合对性别是否存在影响。研究结果发现,共有5个标记组合在P<0.05显著水平上被检测出来,其中组合SCAFFOLD149₇459和SCAFFOLD7854₇1905在P<0.01水平上显著;5个交互组合位于7个常染色体的9个标记当中,这些标记主要集中在连锁群2、10和11,其中连锁群10-11发现了两个差异显著的交互对,且两个交互对均有SCAFFOLD149₇459,说明SCAFFOLD149₇459可能在互作过程中具有较大的影响。研究表明这些标记附近的基因参与了半滑舌鳎的性别决定,也即常染色体可能参与其性别决定的过程,这对进一步研究半滑舌鳎的性别决定和性别控制具有重要意义。